Process and apparatus for producing felted fibrous board



Nov. 18, 1930.. E. s. SHEPERD PROCESS AND APPARATUS FOR PRODUCING FELTED FIBROUS BOARD Filed Sept. 6, 1928 6 Sheets-Sheet l d Nov. 18, 1930. E. s. SHI-:PERB

PROCESS AND APPARATUS FOR PRODUCING FELTED FIBRQUS BOARD Filed Sept. 6, 1928 6 Sheets-Sheet 2 wel? far.-

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Nov. 18,- 1930. E. s. sHEPERD. 1,732,214

PROCESS AND APPARATUS FOR PRODUCING FELTED FIBROUS BOARD Filed Sept. 6, 1928 v6 Sheets-Sheet 3 gs A 5:

Nov. 18, 1930.

E. s. SHI-:PERO "1,782,214 PROCESS AND APPARATUS FOR PRODUGING FELTED FI'BRoUs BOARD Filed Sept. 6, 1928 6 Sheets-Sheet 4 n ,f f N n I l l l l 4 l/ I l5 v'. N r A 3 l *5 l o N l 0 0 a a5 x m l, Q\ o d V w QP H*- l/ G 9 o f/o@ o fwd 064 u; /K a v Nov. 1s, 1930. ESSHEPERD f 1,782,214

PROCESS AND APPARATUS FOR PRODUCING FELTED FIBROUS BOARD Filed Sept. 6, 1928 6 Sheets-Sheet 5,

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Nov. 1s, 1930. E. s. SHEPERD f 1,782,214

PRGCESS AND APPARATUS FOR PRODUCNG FELTED FIBRDUS BOARD Fi1easepte, 1928 e sheets-sheet e Patentedl Nov. 1s', 1930 p' 1 UNITED STATES PATENT oFFlcE EDWARD S. SHEPED, OF ST. JOSEPH, MISSOURI, ASSIGNOR TO ALBERT D. STEWART, OF ST. J'OSEPH MISSOURI :PROCESS AND APPARATUS F013.` PRODUGING FELTED FIBROUSBOARD Application .iiled September The present invent-ion relates more particularly to a rocess and apparat-us especially designed or producing a lfelted fibrous board from cereal straw fibers.

In recent years there has been developed a number of types of boards having thicknesses of approximately '0/8 to particularly adapted for insulating and sound deadening purposes. Some of these boards belong to that class which can be used as substitutes for lumber, that is,'they' have the necessary inherent structural rigidity and stiffness to permit substitution thereof. for lumber. It is in this class of board that theboard product of the present invention is classified.

I are to provide an appartus making use of two rotatable feltinor cylinders, one preferably disposed on a plane slightly lower than the other; to provide an apparatus so designed as to continuously produce a board of uniform characteristics; to provide an apparatus -comprising two rotatable felting cylinders disposed above, and in communication with a specially designed forming or pulp suspension receiving chamber, characterized 1n that the latter is located substantially centrally between the two forming cylinders so that the board as felted or formed passes upwardly between the two cylinders.y to which latter pressure is applied to secure the necessary extraction of water to produce a board sufficiently dry to allow its transfer to a carrying belt or other instrumentality leading tothe l press and drying parts of the machine; to

provide an apparatus by which the board may be produced as a continuous sheet; to provide in a construction ofthe character described stationary end seals attached to said forming chamber to effectively prevent e, 192s. serial No. 304,254.

leakage of the pulp solution; to provide seals b etween the ends of the two cylinders and the ends ofthe adjacent forming chamber by providing grooves in each end of each forming cylinder disposed oppositely to each other, in which the edges of the seals ride; to provide a stationary seal effectively performing its sealing function regardless of the rotation or lateral movement of the two felting cylinders; to provide a stationary seal of the character described capable ofrautomatically adjusting itself to all positions of the two cylinders; to provide in a construction of the character described separate, independently controlled inlets for the admission of the pulp solution tothe forming chamber; to provide in a construction of the character last ldescribed a bottom inlet preferably located at t-he extreme bottom ofthe forming chamber, and an upper inlet located adjacent the upper end of the forming chamber as near as possible to the point where the sheets formed on the two cylinders meet and are united into a single sheet of board; to

provide in a construct-ion of the character described a specially designedlower inlet comprising a plurality of abutting freely communicating chambers, each having an inlet disposed centrally thereof and. at the, low point of each'chamber, the lower surfaces of the chamber from the center inlet tapering upwardly to the ends to form a progressively increasingly restricted passageway; to provide in a construction of the character last described` a longitudinal opening in the upper edge of each chamber discharging the pulp solution into the forming chamber proper; to provide in a construction of the character described an upper inlet disposed within thc forming chamber and preferably taking the form of an elongated oval, the upper edge thereof heilig provided with a longitudinal opening through which the pulp solution fed thereto discharges into theforlning chamber tudiual seals disposed between the upper outer longitudinal edges of the forming chamber and the adjacent cylinder to prevent leakage of the pulp' solution at that point; to provide a machine designed to operate etliciently and effectively with a minimum of mechanical working partis; to provide a ma- 1 chine vin which repair and replacement can be different character can be fed through the upper inlet; to provide a process and apparatus in which the forming of the sheet on the felting cylinders takes place under the inuence of the hydrostatic head pressureof the liquid charged to the lower and upper inlets of the forming chamber; to provide a ,process and apparatus in which the water removed during the forming operation flows through each cylinder and discharges beyond said longitudinal seals, washing the surfaces of said cylinders to remove pulp carried thereon, thus eliminating the necessity for using auxiliary showers i for this purpose, while at the ,samel time being discharged at a point away from the point where such water might tend to back up on the sheet already formed and re-float the fibres; to provide an apparatus in which all flow pipes from the head box to the forming chamber are so designed as to maint-aina uniform flow of pulp suspension from the time. it leaves the head box until it reaches the formingwire; to provide a process and apparatus in which the amount of water contained inthe board after -it is stripped from the lower forming cylinder is regulated entirely by the extentof pressure applied by the two lforming cylinders against the board as the two sheets are being united and passing between said cylinders; to provide an apparatus in which the distance between the two cylinders may be varied; and in general to provide an improved process and apparatus ofthe character referred to.

In thedrawings, Fig. 1 is a side elevational view of the apparatus of the present invention.

Fig. 2 is an enlarged end elevational View of the two felting cylinders illustrating the mechanism for adjusting the position of one cylinder relative to the other.

Fig. 3 is a cross sectional Aview taken on line 3-3 of Fig. 1 looking in the direction of the arrows. v

Fig. 4 is a cross sectional view taken on line 4-4 of Fig. 5..

tive view illustrating the engagement'be-- tween the longitudinal seal and the outer edge of the forming chamber.

Fig. 8 is a cross sectional view taken on line 8--8 of Fig. 5 looking in the direction of the arrows.

Fig. 9 is a cross sectional view taken on line 9--9 of Fig. 5 looking in the direction of the i I arrows.

Fig. 10 is a fragmentary vertical sectional View to illustrate the construction of the forming cylinders.

Fig. 11 is a fragmentary vertical sectional view illustrating the manner in which the sheet forms on each cylinder; theimanner in which it is removedfrom one cylinder and united with, the sheet on the other cylinder; andillustrating specifically the functioning of the upper inlet.

Fig. l2 is a fragmentary end elevational view of the board manufactured by the process and apparatus of the present invention.

Fig. 13 is a cross sectional View taken on line 13-13 of Fig. 14.

Fig. 14 isa cross sectional View taken on line 14-14 of Fig. 13.

Referring more in detail to the drawings, Clearwater is fed under suitable pump pressure through either or both of the inlets 1 to a water reservoir 2. The water tank 2 is disposed at a considerable height preferably immediately below the ceiling or roof of the building in which the apparatus is located, and is provided with two separate drawoifs 3 and 3, controlled respectively by valves 4 and 4". Each of the pipes 3 and 3 discharges into a larger pipe 5 and 5. The pipes 5 and 5, are disposed at the base of a hea-d box 6.

The design of this head box is peculiar to the apparatus of the present invention and in its preferred form. is divided longitudinally by means of baflles 7 and 7 into three longitudinal compartments 8, 8" and 8. The arrangement is such that straw pulp in lflll suspension after having been suitably shredded, beaten and washed is forced from the usual stuft chest through the pipe 9 into the compartment 8, flowing therethrugh in such a. manner that said straw pulp suspension is.

maintained lin motion, the excess not used 'being returned through the overflow pipe 10 to the stuff chest.

Each of the partitions 7 and 7 is provided with a gate valve 11 and 11', respectively, for a purpose 'to be hereinafter described. An inlet 9'communicates with the compartment ico rough the pipe 9 into the compartment 8.

By proper manipulation `of the gate valves 11 and 11 a regulated quantity of the pulp suspension fed to the compartments 8 and 8 may flow into the mixing compartment 8, wherein admiXture takes the fibers in each of the suspenslons, being removed from the compartment 8 through the discharge pipe 5.

As heretofore described, the water charging pipe 3 discharges directly'into the pipe 5 and acts to dilute the pulp suspension to the consistency desired, and since this water is under some head, it will discharge with more force into the pipe 5 than the pulp solution fiowing thereto, acting in effect to break up any clots of fibers which might have formed due to stagnation, thus causing said fibers to again float as separate fibers in the Water. The compartment 8 is provided with an overflow 10 functioning similarto the overflow 10 previously described.

As a feature of the present invention, the compartment 8. is divided transversely by means of a partition 12 to provide a compartment 12. The partitions 7 and 7 forming the compartment 12 may be provided with gate valves 13 and 13 similar to the gate valves 11 and 11', the arrangement 'being such that regulated quantities of the pulp suspension flowing inthe 'compartments 8 and 8 may be fed into the compartment 12 for a purpose to ybe hereinafter described. The pipes 5 and 5 discharge into the conventional flow ,box 13a provided with the baffies 14 yalternately disposed to impart an up and downvflow to the pulpsuspension. In the present instance the fiow box 13a may be divided transversely by means of the partition 15 into two compartments 16 and 16. The pipe 5 discharges into the compartment l'while the pipe 5 discharges into the `compartment 16. The pulp suspension flowing over the last baffle in the compartment 16 may be removed therefrom through the enlarged outlet 17, while the liquid leaving the last baffle in the compartment 16 discharges through the pipe 17. The amount of water contained in the pulp suspension is carefully predetermined and controlled so as to control the thickness and amount of fiber in the finished dry board. For this purpose,l the reservoir 2 may be provided with a water overflow 2 whereby excontrolled by controlling the material place between chamber.

'on the perch 19 supported on the supporting structure 20 which also supports the flow ,boxl 13a. The perch 19 is made exceptionally large to permit an operator to move around thereon for adjustment of the Igates and valves heretofore described to vary the thick- 4 lness or Weight of board in the finished product. v

The discharge 17 terminates in a plurality of branches 21 of similar size, each of which communicates with the center of a chamber 22. There may be a number of these chainbers 22 disposed in abutting freely communieating relation to each other, each chamber being supported as illustratedat 23; 24 illus-l trating the f'loor,

As a feature of the invention, each of the chambers 22 is of a partcula-r design, the inlet 21 being disposed centrally of each chamber 22 and at'the lowest point in thel From the center opening 21 each side of each chamber tapers upwardly, as illustrated, at25 (Fig. 4) toward its end. Each chamber preferably comprises two `halves united by means of bolts, rivets or other suitable locking elements registering with the holes 26 provided for that purpose, and in cross sectional view each complete chamber takes the form of an oval of greater area at its center and` decreasing in area toward each end from the center.

Pulp suspension fed through each of the branches 21 to each of the chambers 22 is caused to have a uniform flow and circulation in the chamber 22 due to its construction. Thisis obvious, since at the point of introduction of the pulp suspension into each of the chambers 22, each chamber has the great-l est area'and decreases in area from `this point toward each end. Thisavoids any danger of dead spots or accumulations of fiber which would result in clogs or slugs of the fiber passing through the machine intermittently.

.the forming area of the two felting cylinders 29 and- 29', resulting in a uniformly formed sheet of board on each cylinder as regards thickness and formation.

The specific design-of the forming chamber 27 tends to carry the fibers entering through the bottom inlets 21 and 28 directly to the wire covered surfaces of the two cylinders as these surfaces enter the forming chamber past the longitudinal seals 30, thus forming -y their outsiderim'a series of longitudinally disposed heavy wooden bars 33 arranged parallel with .the supporting shafts 31 and 31', these bars being arranged with open spaces G to 11/2 apart) between them to ermit i free and unrestricted passafe of water uring the process of formation oit'j the desired sheet of board. Over these wooden bars or slats a heavy bronze or other heavy metal Wire 34 is wound, preferably spirally, from end to end of the cylinder as a foundation to receive a covering of one or more plies of metal cloth or screening 35` appliedto complete a suitable forming surface for proper felting of the board. l

The cylinders 29 and 29 Vare mounted on suitable supporting frames 36 and 36, respectively, on which-are mounted bearings 37 and 37', respectively. The bearings 37 may be stationary, while the bearings 37 for the eylinder 29 may be adjustable in the direction of the stationary cylinder 29 to allow for adjustment of pressure to remove the necessary amount of water from the formed sheet of board. These means for adjustment will be hereinafter more particularly described.

The two cylinders 29 .and 29 are geared together'by means of the gears 38 and 38 to insure uniform rotation as regards' each other.

' Power may be transmitted to the gear 38 and from the latter in turn to the gear 38 through the pinion gear 39 mounted on shaft 40, which in turn carries a large gear 41 meshing with a spur gear 42 4mounted on shaft 43 and receiving rotation from the pulley 44 and belt 45. The forming chamber 27 is located substantially centrally between the twoform'ing cylinders 29- and 29 to which pressureis applied toward each other to secure the necessary'extraction of Water to produce a board sufiiciently dry to allow its transfer to the carrying belt 46 leading to the press and drying parts of the machine. I

Returning now to the lower inlet 2l, and

. the outlet 28 therefrom into the forming chamber, the pulp suspension fed therethrough will be forced to the surface of each of the slowly rotating cylinders 29 and 29 and due to the hydrostatic head maintained on said pulp suspension the water will pass directly through each cylinder, discharging on the opposite side thereof just beyond the longitudinal seals 30 insuch a manner as to wash such surfaces free of any pulp carrled therepn. This latter step is important, slnce `it eliminates the necessity for using a shower usually employed for the purpose of cleaning the cylinder walls. It is also important at this point to note that the water is removed at a point where it will not flow back on the board being formed, which would result in breaking the bond between the fibers and rcstore them to a condition of fiotation in a water vehicle. This is one of the objections to many of the apparatus now in general use for the roduction of a board of the character pro uced by my machine.

The longitudinal seal 30 is provided on each of the opposite outer edges of the forming chamber 27 and comprises rubber or the like contacting the faces of the screen and sealing against any leakage at that point. The seal may be fastened' to the angle iron upper edge of the forming chamber 27 by any suitable means, such, for instance, as a clamp bolted thereto.

Referring now to another feature of the present invention, the upper inlet 47 is charged from both ends through the branches 48 and takes the form of an oval shaped pipe, provfded on its upper. surface with a narrow longitudinal continuous slot 49 approximately 1/2 tolll wide, more or less. In the use of the top inlet in the present apparatus,

I introduce clear Water or a solution of WaterV and pulp of any consistency or nature at the point where it is possible to set up a counter flow action in the forming chamber, thus causing a mild disturbance at that point,

which results in a more rfect formation and felting of individual bers, insuring the strongest, and at the same time the lightest weight board for algiven thickness. This inlet also permits the insertion of fiber of an entirely different composition and nature relative to that already formed on the cylinders from the pulp solution admitted through the bottom inlet, giving a control over the lamination and interior structure of the board superior to that which can be obtained in any other process of formation of which I am aware.

As has been explained, the purpose of using the upper inlet 47 is to maintain at the point where the two sheets are coming together a circulation of liquid and proper consistency of stock in suspension so as to reterminating at a point disposed slightly above `the upper contacting point between the two forming cylinders. One of these seals is disposedon each end of thercylinders and is adapted to register with the` cylinders, through the medium of opposed annular f grooves 51 in` the cylinders, thus preventing any Water or pulp from leaking beyond the ends ofthe cylinders. The grooves 51 may be formed by placing annular rings on the ends of the cylinders a suicient distance away from such ends and at a depth of approximately 11/2 to 2" more or less to accommodate the seal. These seals may be held Securely `in place against the end walls 52 of :the forming chamber by means of clamps or other suitable locking elements 52 and bolts or other locking elements 53 passing through the holes 53 in the end wall 52 and seal 50, thus holding the seals securely in registration with the grooves adjacent the ends ,of the cylinders. Due to the fact that each groove is from 11%2 to 2" deep, more or less, and furthermore, since the edges of the seal register in sald grooves to the greatest possible extent when the cylinders are close together, it is obvious that the movable cylinders can-be adjusted within a latitude up to 1% and yet have the seals automatically accommodate themselves to such movement. Yet, the seal is` simple in construction and eflicient in use.

. with opposite ends of the upper conduit 47 In Fig. 11 I have attempted to diagrammatically illustrate the manner in which the fibers form on each of the cylinders 29 and 29 and the manner in which the two sheets thus formed come together and are united and interlocked to form a single unitary sheet 54 which is taken on the forming cylinder 29 T and passed to the receiving belt 46. It is to be understood that this is merely diagrammatic for the purpose lof a clear understanding of the invention. The branches 48 communicate through the walls of the end closures 52 of the forming chamber.

The supporting frames 36 and 36 are connected together by means of an adjustable screw bolt 55. 'As heretofore stated the bearing 37 is a stationary bearing, while the bearing 37 is movable. A yoke 56 is mounted on the supporting structure 36. A movable arm 57 depends from the center of 'said yoke 56, being pivoted at 58. The arm 57 carries the bearing 37 thus permittin said bearing to be moved back and forth an with it the cylinder 29. The positioning of the movable bearing isregulated .by obvious manipulation of the adjusting screw 59 against the tension of the coil spring 60, said spring functioning to press the cylinder 29 against the board passing between the two cylinders.

The operation should be apparent from the foregoing description. Instarting the machine, power is transmitted'through the belt 45 and pulley 44 to the gears 38 and 38 whereby the forming cylinders 29 and 29 areslowly rotated, the cylinder 29 in a clockwiseV direction and the cylinder 29 in va countervclockwise direction. The proper amount of water is const-antlycharged to the reservoir 2 so as to maintain at all times a predetermined head as well as a predetermined volume of water. Pulp solution is constantly fed to the `of the forming cylinders 29 and 29 to produce a board of the desired thickness and weight, clear water may be charged to the compartment 12 through the p ipel 3, passingthrough the pipe 5, compartment 16 of the iiow tank 13a, branches 48 in'to the upper inlet 47, through the mouth 49" and charged immediately adjacent the point at which the two sheets forming on the cylinders 29 and 29 come together. In the same manner, should it be desired to incorporate "stock in the chamber 12', this can be done by proper manipulation of the gates 13 and 13, in which event a thin suspension may be proj ected through the mouth 49 instead of clear water. The adhesive qualities of news print and similar paper pulp is 'well known, and advantage might be taken of this fact to project such type of pulp directly into the nlp at the point where-the two sheets are coming made is controlled .entirely by regulating the consistency and amount of stock, all of which is controlled at the vhead boX 6 relative to the speed of rotation of the forming cylinders.

The hydrostatic head forcing liquid to the sol called upper inlet 47 sis alwaysslightly greater than the hydrostatic head forcing thmepulp suspension to the lower inlet so that there will be proper balancing of pressure within Ath'e forming chamber, i. e., so that none of the pulp suspension discharging through the mouth 28 will back up through the mouth 49.

.As a feature of the invention, attention is back down on the sheet being formed, caus-i ing variations in theA thickness and re-floating of the individual fibers inwater.' As a matter of fact, in the present invention the twocylinders 29 and 29 are mounted over-the forming chamber 27 in such a manner that" the center of theforming chambercoincides with and is direct-ly below, the nip where the sheets carried by the two.cylinders come together. While I have shown two chambers 22, it is `obvious that I may use one or more. I have found that two can be efficiently used with a machine having cylinders approxi-- mately thirteen feet inlength and or larger in diameter.

The amount of water contained in the board after it is stripped from the lower forming cylinder is regulated entirely by the pressure applied by t e two forming cylinders against the board through the medium Vof the compression coil spring 60. lNormally, the two formin cylinders are separated about 1/8 to 1/2 w en no pulp is passing between them, this separation being brought about by an typeof adjustable stop, pref-v erably an a justable bolt 55. When ulp is passing between the two forming cy inders in the formation of a sheet, the movable cylinder gives,7and the tension of the s ring provides proper pressure to remove t e desired amount of water from the felted board.

As the..board 54 leaves the forming cylinder 29|', the'thickness thereof maybe determined in any conventional manner, for instance, through the medium of avisual device, comprising a roller contacting with the raise or lower a column of colored liquid in a suitable glass tube which' can be observed by t-he operator. It is to be understood that `any device for effectively determining the thickness of the board leaving the form'ng cylinder 29 may be employed. The cyhn er 29 is disposed on a lower plane (about 4,

more or less) relative to cylinder 29 so that the board 54 will be carried on the cylinder 29 to the belt 46. The cylinders preferably are' of the same diameter.

As a feature of the invention it is to be noted that the stock is fed upwardly and collected on the forming cylinders while they are both moving upwardly, as distinguished and collects on the surface of the forming cylinders while the latter aremoving downwardly or in a horizontal plane. It has always been diiiicult in the operation of the type of machine of the present invention to secure a perfect seal between the ends of the two cylinders and t-he ends of the forming chamber. This seal is accomplished in the present invention in a very effective and economical manner, and while it is -stationary, it functions perfectly in all positions of the two cylinders within any rangeof practical use.

vWhile I have designated cylinder bearing 37 as being stationary and cylinder bearing 37 as being movable, itI is obvious that this is just for purposes of illustration. The bearings of either cylinder may be made stationary, and correspondingly `the bearings of either c linder may be made movable.l It may be gound to be of advantage to make the cylinder 29 the movable cylinder rather than the cyhnder 29.

I have found that the design of the forming chamber 27 is' of importance in that its shape has very much to do with the successful formation of a Yheavy sheet of fibrous board. Its cross-sectional area, as shown in y Fig. 5, should be proportioned in exact relationto the speed at which the sheet of board is formed.

Cross reference is made to my co-pending application 304,255 wherein the novel sealing means herein described, is reserved and claimed. v

-I claim as my invention:

l. A machine comprising in combination forming cylinders geared'toget'her to rotate in unison, a forming chamber disposed below said formin cylinders substantially central. ly of the bite between, and communicating with, said forming cylinders, a sealfdisposed adjacent the sides of the forming cylinder for preventing leakage ast the sides of the forming cylinder and lt e forming chamber and separate inlets for suplying water and pulp to said forming cham er, one disposed adjacent thelower end thereof and the other disposed above said lower inlet.

2.A machine comprising in combination, forming cylinders geared together to rotate in unison, a forming chamber disposed below said forming cylinders 'substantially centrally of the bite between and communicatin with, said forming cylinders, a seal disposed adjacent the sides of the forming cylinder for'preventing leakage ast the sides of the forming cylinder and t e forming chamber and Vseparateinlets for supplying waterjand pulp to said forming chamber, one disposed adjacent the lower end thereof and the other disposed above said lower inlet, the discharge from the lower inlet to the forming chamber to said forming'chamber, one dis osed adjacent the lower end thereof an the other disposed above said lower inlet, the dlscharge from the lower `inlet tothe forming chamber being disposed centrally below the point at which the sheets carried by said cylvmders come together, and the discharge from said upper inlet to the forming chamber being disposed in the same vertical plane as the v discharge from said lower inlet..

4. A machine comprismg 1n combination, forming cylinders geared together to rotate in unison, a formin chamber disposed below said forming cylin ers substantially centrally of the bite between and communicatin with said forming cylinders', a seal dispose adjacent the sides of the forming cylinder for preventing leaka e past the sides of the forming cylinder an the forming chamber and separateinlets for supplying water and pulp to said forming chamber, one disposed adj a:-

cent the lower .end thereof and the'other disposed above 4said 'lower inlet, means -for chargin the lower inlet with pulp suspension an separate means, independently controlled, for charging said upper inlet.

5. A machine comprising 1n combination,

forming cylinders geared together to rotate 1n unison, a formlng'chamber disposed below vsaid formin cylinders substantially centrally of the ite between and communicating with said forming cylinders, a seal disposed adjacent the sides of the forming cylinder for preventing leakage past the sidesof the forming cylinder and the forming chamber and separate inlets for-sup lying water and pulpito said'forming cham er, one dlsposed disposed above said lower inlet, the discharge from the lower inlet to the forming chamber being disposed centrally below t e pomt at which the sheets carried by said cylinders the sheets carried by said cylindersquantities of same to a felting instrumentality to cause two sheets to be simultaneously formed, thereafter uniting said `sheets while still wet to produce a single sheet, and immediately adjacent the point at 'which said sheets are united introducing a regulated quantity of water to cause a mild disturbance at that point.

7. A process of forming a relatively thick felted fiber board, which comprises main'- taining a hydrostatic pressure on pulp suspension, continuously feeding regulated quantities of` same] to a felting instrumen. tality to cause two sheets to be simultaneous-- ly formed, thereafter uniting saidl sheets while 'still wet to produce a single sheet,.and

immediately adjacent the point at whichsaid `sheets are united introducing a regulated verge upwardly away from said inlet on opposite sldes thereof and which terminate intermediate the height of said chamber, and a pair of forming cylinders adapted to rotate in unison through the chamber above the upper en s of said walls and in close proximity tosaid ends.

, 9. A machine comprisin in combination,

`a forming chamber, an in et for pulp suspension at the lower portion of said chamber, said chamber havingv side walls which di-v verge upwardly-away from said inleto'n opposite sides thereof and which terminate in termediate theheight of said chamber, means for introducing water to said chamber at a` point above said inlet, and a pair of forming cylinders adapted to rotate in unison through the portion of said chamber above the upper ends of said walls and in close proximitv to said ends".l

In testimony whereof I affix my signature.

EDWARD S. SHEPERD.

(portion of said j 

